1. Guyton 2011 Chapter 9

3. Semilunar ValvesAv Valves Mitral Tricuspid Aorta Pulmonary

5. Low frequency Loudest and longest High frequency Shorter duration Low intensity In children with thin chest wall and heart failure In early diastole Atrial contraction Occasionally in healthy individual S1 S4 S2 S3

6. The Force-length Relationship of Myocardial Fibers

8. Muscle Length and Force of Contraction Passive Tension Total Tension Active Tension

9. The Volume – Pressure Relationship of Myocardial Fibers

10. 10 Ventricular Pressure-Volume Relationship End -Diastolic Ventricular Volume (EDV) End -Systolic Ventricular Volume (ESV) Stroke Volume (SV) Ejection Fraction (EF) = SV/EDV

11. 11 Points Efficiency of Cardiac Contraction In normal condition is about 20-25 percent In heart failure is as low as 5-10 percent Preload and Afterload Chemical Energy Required for Cardiac Contraction 70 to 90 percent derived from oxidative catabolism of fatty acids 10 to 30 percent from other nutrients especially lactate and glucose

12. 12 Regulation of Heart Pumping Intrinsic Regulation Frank-Starling Extrinsic Regulation Nervous Control

13. 13 Intrinsic Regulation of Heart Pumping The Frank-Starling Mechanism

14. 14 Intrinsic Regulation of Heart Pumping The Frank-Starling Mechanism

15. 15 Extrinsic Regulation - Nervous Control

16. 16

17. 17 Effect of Potassium and Calcium ions on Heart Function CaK  Arrest in Diastole Bradycardia Arrest in Systole Bradycardia

18. 18 Effect of Temperature Heart Function Effect of Temperature Heart Function  Tachycardia Bradycardia

19. The End